Affiliations: Department of Biochemistry, University of Allahabad, Allahabad, India
Note: [] Corresponding author: Dr. Syed Ibrahim Rizvi, Department of
Biochemistry, University of Allahabad, Allahabad, 211002, India. Tel.: +91
9415305910; E-mail: [email protected]
Abstract: Sialic acids are substituted neuraminic acid derivatives which are
typically found at the outermost end of glycan chains on the membrane in all
cell types. The role of erythrocyte membrane sialic acids during aging has been
established however the relationship between sialic acid and oxidative stress
is not fully understood. The present work was undertaken to analyze the
relationship between erythrocyte membrane sialic acid with its plasma level,
membrane and plasma lipid hydroperoxide levels and plasma total antioxidant
capacity. Results show that sialic acid content decreases significantly
(P< 0.001) in RBC membrane (r= −0.901)
and increases in plasma (r=0.860) as a function of age in
humans. Lipid peroxidation measured in the form of hydroperoxides increases
significantly (P<0.001) in plasma (r=0.830) and RBC membranes (r=0.875) with age in humans. The
Trolox Equivalent Total Antioxidant Capacity (TETAC) of plasma was found to be
significantly decreased (P< 0.001, r=−0.844). We observe significant correlations between decrease of
erythrocyte membrane sialic acid and plasma lipid hydroperoxide and TETAC.
Based on the observed correlations, we hypothesize that increase in oxidative
stress during aging may influence the sialic acid decomposition from membrane
thereby altering the membrane configuration affecting many enzymatic and
transporter activities. Considering the importance of plasma sialic acid as a
diagnostic parameter, it is important to establish age-dependent reference.
